Molecular interactions in substituted 2,2′-bipyridines: crystal structures of 2,2′-bipyridine-3,3′-dicarboxylic acid monohydrate and (2,2′-bipyridine-3,3′-dicarboxylic acid)dichlorocopper(II) dihydrate

In the monohydrate structurea=8.315(1),b=8.578(1),c=16.952(2)Å, Orthorhombic,P2₁2₁2₁, there are intramolecular interactions between the O atoms of the carboxyl groups and the C2 atoms of the opposite rings. The water molecule present in the structure is involved in an extensive network of hydrogen bonds. In the dichlorocopper(II) dihydrate complex structurea=12.442(1),b=19.614(1),c=14.481(1)Å, β=94.38(1)°, Monoclinic,C2/c, the Cu(II) is coordinated to two Cl atoms, two N atoms of the bipyridyle ligand and a water molecule. There are possible Cl ion bridges between the two Cu atoms to form pseudo-discrete dimers. The uncoordinated carboxylic acid groups and the water molecules, present in the complex, form an interesting network of hydrogen bonds.